1. Field
Embodiments relate to the determining of adjustments of storage device timeout values based on synchronous or asynchronous remote copy state.
2. Background
One or more storage controllers may be coupled to one or more of a plurality of hosts. The storage controllers may manage a plurality of storage devices, such as disk drives, tape drives, etc., that are coupled to the storage controllers. The plurality of hosts may access data stored in the storage devices via the storage controller.
One of the storage controllers may be a primary storage controller that is coupled to a secondary storage controller. Data stored in the primary storage controller may be copied synchronously or asynchronously to the secondary storage controller via remote copy operations, where the primary storage controller logical drives may be source drives (also referred to as “source”) and the secondary storage controller logical drives may be target drives (also referred to as “target”). In synchronous copy, write commands from the host to the primary storage controller do not receive a completion message from the primary storage controller, until the data that is written on storage devices controlled by the primary storage controller have been copied over to the storage devices controlled by the secondary storage controller. In asynchronous copy, a host that sends a write command to the primary storage controller receives a completion message from the primary storage controller when the data is written to the storage devices controlled by the primary storage controller, without waiting for the data to be copied over to the storage devices controlled by the secondary storage controller. In asynchronous copy, the data written on storage devices controlled by the primary storage controller may be copied to the storage devices controlled by secondary storage controller after the host has received the completion message.
A redundant array of independent disks (RAID) is a data storage virtualization technology that combines a plurality of disk drive components into a single logical unit for the purposes of data redundancy or performance improvement. Data may be duplicated and/or distributed across the disk drives in one of several ways, referred to as RAID levels, depending on the specific level of redundancy and performance.
In many situations, an input/output (I/O) command may be sent from a host to a storage controller that controls a storage device. A predetermined period of time referred to as a timeout value may be set for the storage device. If the storage controller is unable to secure a response from the storage device within the predetermined period of time after performing operations with respect to the storage device, the storage device is indicated as being timed out for the I/O command.